Investors should not expect the latest market rebound to last much longer and would be smart to take advantage of the higher prices while they can, according to JPMorgan. Strategist Mislav Matejka said in a note to clients Monday that the solid start to 2023 for stocks will quickly prove to be a mirage. "We believe that the current market rally will start fading as we move through Q1 ... Potential curveballs could come from the Fed, politics, disinflation phase not progressing smoothly, weaker earnings, weaker capex and renewed rollover in activity momentum," Matejka wrote. "We believe that one should be using potential gains over the next weeks in order to reduce exposure," Matejka added. The S & P 500 has added 3.7% through the first two weeks of the year, while the Nasdaq Composite has climbed 5.1%. .SPX YTD mountain The stock market is off to a solid start in 2023. The recovery of cyclical stocks versus defensive stocks in recent months is one reason to be skeptical of the rally, Matejka said, in part because an economic slowdown would hurt the earnings of cyclical companies more than those in defensive industries. "The market is behaving as if we were in an early cycle recovery phase, but the Fed has not even concluded hiking yet. Typically, this phase is seen only after a period of Fed cuts. We think the upmove will hit an air-pocket, and end up looking premature," the note said. The Federal Reserve's next meeting is on Jan. 31 and Feb. 1. Traders currently expect the central bank to raise its benchmark interest rate by one-quarter of a percentage point, according to the CME FedWatch tool. That increase would be slower than almost all of its hikes last year, when it mostly raised by a half or three-quarters of a point. — CNBC's Michael Bloom contributed to this report.